As CF says above, you will need the software to code the air suspension out so the light goes off once you remove it but with regard to the change it’s pretty straight forward.
Not suggesting that you buy this kit but looking at it should give you a good idea what you’ll need to grab off the donor car:
https://m.autozone.com/suspension-st..._0_0?location=
Looks like the top mounting plates, bump stops and mounting hardware for the rear and as you said, the front is pretty mush straight forward.
I also found a handful of videos on YouTube that may help you out.
I would also say take some good pics under your car and take those with you to the parts yard, you can compare those to the donor and help yourself out a ton with what you may be missing that it has.
All in all it’s a pretty “easy” job - good luck!
2005 X5 4.4i (04/05 build date)
Titanium Silver w/Black Interior